The purpose of this project is to provide consultative services in statistical and epidemiological methodology in the design, interpretation, and evaluation of clinical trials and other studies requiring this kind of expertise. For some trials the section provides full statistical support including development of detailed study plans, randomization of patients, collection, processing, editing, and analysis of data, and preparation of scientific papers. At present, members of the Section are involved in studies concerned with prostate cancer, testis cancer, breast cancer, lung cancer, brain tumors, and mycosis fungoides. In addition to these major projects, a variety of other consultative activities, including review of scientific articles, arise in response to special requests.